<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>寻路</title>
    <style>
        #ul {
            margin: 40px auto;
            padding: 0;
            border: 1px solid #333;
            border-right: none;
            overflow: hidden;
            border-bottom: none
        }

        #ul li {
            float: left;
            list-style: none;
            border: 1px solid #333;
            border-left: none;
            border-top: none
        }
        #startBtn{display: block;margin: auto}
        .a{background: #aaaa3a}
        .b{background: green}
        .c{background: #a3a3fa}
    </style>
</head>

<body>
    <ul id='ul'>

    </ul>
    <input type="button" value="开始寻路" id='startBtn'>
    <script src="1.js"></script>
</body>

</html>